Hasn’t the burden of disease fallen thanks to improved hygiene and nutrition rather than immunisation?

Prosperity and hygiene are generally linked with better health outcomes. Access to clean drinking water and good hand hygiene are essential in reducing the spread of hepatitis A, typhus, cholera and a number of other infections.

However, hygienic conditions alone are not enough. Some pathogens, including measles, hepatitis B and polio, live in the human body and are spread by coughing, sneezing or sexual contact.

With measles, the risk of infection is closely linked with immunisation rates. If around 95% of children are vaccinated, measles can be eliminated.

Nutrition will not offer protection against infection. The confusion on this question arises from the fact that malnourished children who catch measles tend to suffer a particularly severe form of the disease.

So, good hygiene and clean water can help reduce the risk of some – but not all – infectious diseases. And nutrition has a role in how children react to infection against some viruses but has no bearing on the chances of being infected in the first place.

Large-scale vaccination campaigns in Africa and Asia have helped to dramatically reduce the number of deaths from preventable illnesses like measles.